Method of producing gas.



PATENTED JULYl 14, 1908.

W. B. DENNIS. y METHOD 0F PRODUGING GAS.

APPLICATION FILED MAR.1.1906.

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PATENTED JULY 14, 1908.

W. B. DENNIS. METHODOF PRODUGING GAS.

APPLICATION FILED MAR.1.190G.

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PATENTED JULY 14, i908.

W. B. DENNIS. METHOD 0F PRODUGING GAS.

APPLICATION FILED MAR. 1. 1906,

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No. 893,462. PATENTED JULY 14, 1908. W. B. DENNIS. METHOD 0F PRODUGING.GAS.

'APPLICATION FILED MAR.1,1906.- A,

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*UQWTED @TTES WILLIAM BDENNIS, OF

BLAOKBUTTE, OREGON.

METHOD OF PRODUGING GAS.

specification of Letters Patent.

Patented July 14, 1908.

Application filed March 1, 1906. Serial No. 303,692.

To altwhom it may concern."

Be it lknown that I, WILLIAM B. DENNIS, a citizen fof the United States,residing at Blacklnltte, in the county of Lane, Oregon, haveinventedcertain new and useful Improvements in Methods of Producing Gas; and ldo hereby-declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the. same.

My invention relates to improvements inmethods of making producer gas,and it is intemled more especially for making producer gas from any kindof fuel for use in furnaces, lbut it is not confined to this use, as itmay be used for all metallurgical and heating purposes, and also forpower and illuminating purposes, when properly scrubbed enriched andcooled as may be required.

The distinctive feature of my method consists in oxidizing the fuel massgradually, or by degrees, in progressive Zones of combusev tion, by theadmitting to each zone a volume of air measured in proportion to thetemperature of the fuel in suc'n zones and of causing the evolved gasesand vapors of each zone topass into and through the next succeeding zonein the line of progression of the combustion process, the travel of theevolved gases or products of combustion being always from 'a zone oflesser to one of more advanced combustion, or from a cooler to a hotterzone. Beginning with the zone of incipient combustion the evolved gasesmoving from Zone to zone pass through the entire fuel mass, and arcdischarged from the hottest Zone of final combustie'm at a point belowthe last air inlet of the combustion series, andthe evolved gases, orcombustion products, are caused,

after being discharged from the last or final oxidizing zone at a pointbelow the last air inlet of the combustion series, to passinto andthrough a reducing or enriching zone or rece tacle containing higlilyheated or vin-I crmdiiscent carbon, and preferably to pass through saidcarbon, and into which zone no oxygen or air is admitted other than thatalready contained in the fuel gases admitted thereto. In combinationwith the foregoing, I also preferably employ whatis commonly known as adown draft, preferably produced by mechanical suction. This method ofoxidizing fuel and generating heat and gas therefrom may be convenientlydescribed gradual combustion and in practical operation it consists ofdividing the fuel mass and the receptacle containing it, into a seriesof units or zones and of supplying each unit with the minimum amount ofoxygen, or air, which can chemically combine with the f uel elements atthe temperature of such unit, thereby procuring the decomposition of thefuel gradually, beginning with the initial unit of nascent combustion atone end of the fuel mass or receptacle and progressing from unit tounit, or zone to zone, until comlete decomposition is accomplished atthel ast or final zone of combustion. By this rnethod perfect chemicalunion of the evolved fuel elements -with the air at or near thetheoretical chemical minimum is secured, resulting in the completegasification of the fuel and the production of a uniform gas free oftarry impurities. The uniform constituency ofthe gas is further assuredby causing it to pass through a reducing Zone as above described.

The process is simple, economic and harmonious, and is especiallyvaluable in gasifying large masses of fuel.

In making gas', oftentimes the volume of air required tosupport'combustion of the entire fuel mass is admitted at one or morepoints, usually an excess volume, and without regard to the temperatureor chemical requirements of the fuel at the point of admission. Underthese conditions perfect mixture and the complete and uniformgasification of the entire fuel mass is impossible. The fuel zoneimmediately adjacent to the admission point burns rapidly with a greatexcess of air while areas of the fire farther removed are not suppliedwith sufficient oxygen to support perfect combustion. Under theseconditions uniform elememiary change throughout the combustion area isimpossible. A confusion of chemical actions and reactions is set up, dueto imperfect mixture and greatly varying temperatures within narrowlimits, resulting in loss of fuel values due to incomplete decompositionof some portions of it and in the production of an un-uniform gas, andthe highly objectionablc semi-distillation products.

By my method of gradual combustion the air is supplied at frequentintervals, to each unit or zone in amount proportional to the capacityof the fuel elements in such Zone to chemically combine therewith, themeasure of which capacity is the temperature of the fuel in such unito1' zone.

. In the zone of incipient oxidation, where the temperature 1scomparatlvely low only water vapor (U) isliberated, and only sufficientair is supplied to produce this result.l In the next zone of the seriesthe teinperature being somewhat higher than the preceding one, thelighter hydrocarbons are released, and sufficient additional air only issupplied to support this degree of combustion. In like manner from zoneto Zone the process of combustion is advanced gradually, or by degrees,and sufficient additional air is supplied to each zone to support theproportional duty of that zone to the whole process, until completeoxidation has been accomplished finally in the last combustion zone ofthe series, and the gaseous products are delivered into the reducingchamber, as previously described, where the well known chemical reactiontakes place resulting in reduction of the carbon dioxid (CO2) and water(H2O) into carbonic oxid (CO), and hydrogen (H). These gases, as theypass to the holder, or to the place of consumption,

are of course mixed with the nitrogen of the' air admitted into theproducer.

It is evident that by this method, which is exceedingly simple andcapable of general application, perfect mixture of air withthe evolvedgases is secured', that the supply of air may easily be regulated inproportion to the chemical requirements, and that the entire fuel bodyis uniformly oxidized without any of the ob'ectional semi-distillationproducts, and wit out vloss of any portion of the calorific value of thefuel.

The above method is applicable to generating heat and gas from any kindof fuel and may be carried out in various forms of appa` ratus, one ofWhichis shown in the accom panying drawings, in which- `Figure 1 is avertical section of a gas producer for carrying out my improved methodas applied to a roasting furnace Fig. 2 is a horizontal cross section ofthe same; Fig. 3 shows the manner of generating and supplying gas to anengine, showing the gas producer and scrubber in cross sec-tion, agasometer, and an engine, and Fig. t is a vertical cross section of amodified form of my gas producer.

In the drawings I have shown in Figs. 1

and 2 one suitable form of a gas producing',v

of suitable [ire resisting material and upon which are retained the livecoals which drop `through the upper or fuel grate until such coals havebeen reduced to ashes. In a convenient position underneath or beyond thereducing chamber is the gas passage and ash pit. The grate floor of thereducing chamber may be o'lnitted, if desired, and the gas passage usedas a reducing chamber. The operation of this gas producer is as followsThe fuel is fed through a hopper at the to and the fire being started,the fuel receptac e is kept well filled. The valve controlling the topair inlet of the series is opened sufficiently to admit the requisite voume of air, the measure of which is the temperature of the correspondingfuel zone. In like manner the remaining air inlets of the series, alwaysunder separate control, are opened sufficiently to admit the requisitevolume of air corresponding to the duty of each zone as previouslydescribed, always proportional to the temperature of the fuel therein.

The gaseous products of each zone are ulled downward always from acooler to a iiotter zone as described, a suction draft being employed.Finally the gases are discharged into the reducing chamber at a pointbelow the last airv inlet of the series, and after passing through thereducing chamber in the presence of highly heated or incandescent carbonare discharged underneath the grate thereof into the gas passage leadingto the gas holder, combustion chamber or furnace,

as the case may be.

'85 represents the fuel receptacle located on the rear of the furnaceandprovded with a fuel hopper 86 closed by-a swinging cover 87, aconveyer 88 being located in proximity thereto. The fuel hopper isprovided with a sliding plate or door 116, which separates it from thefuel receptacle proper. Connected to the fuel hop er 86 is a smoke pipeor fiue 89, which may fie desirable to use 1n starting the fire, or incase of emergency, when the operation of the suction fan, not shown inFig. 1`, is stopped, and when it is desired to shut off the gas from thefurnace by closing the dampers in the gas passage leading thereto. Thesmoke pi e or flue 89 is provided with a movable va ve 90, which in theordinary operation of the furnace is closed.

91 represents a removable cover in the pi we 89, so that access may -behad to the va ve 90 for the purpose of luting it in position,whenvdesired.

The form of gas producer best adapted for my purpose is of the suctionty e, the air being forcibl drawn in through t e gas producer and te'entire furnace.

The fuel chamber 85 is provided with a grate 93, of any suitableconstruction. Belowthis fuel chamber is the reducing chamber 80, whichis provided with a grate 94 for the purpose of catching and retainingany incandescent coals that may pass through. the grate 93.

Sufficient air, without undue excess, is in troduced into fuel chamber85 to completely oxidize its entire fuel contents. This air is .admittedin regulated quantities throu h several air inlets, asdescribed, ingradua steps of progression so that perfect and uniform mixture issecured. The resultant product of CO2 gas is then drawn off ordischarged from generatorchamber 85 at a oint below or beyond the lastair inlet of tie combustion series of inlets and is delivered to orsucked through reducing chamber which is a closed chamber into which noadditional air is admitted. This chamber being filled, or partiallyfilled, with incandescent carbon, the C()2 gas is reduced to CO by thewell known chemical reaction. The carbon monoXid is now delivered to, orsucked into, gas holder or distributing chamber 97 as described, and isready for use or further delivery as required to coolers, scrubbers, orto direct fired furnaces. Before final use, it is supplied with" therequisite air, preferably heated, and is burned to CO2. The quantity ofair supplied is always in proportion to the temperature of the fuelorgas at the point, or unit, of mixture in accordance with my method ofgradual combustion as described.

The fuel chamber is provided with a number of openings, such as 95, forthe ad'- mission of air. Each opening is provided with a valve 96, sothat the amount of air admitted to any part of the gas producer may beexactly regulated in proportion to the temperature of the fuel in theZone corresponding to each air inlet, and the amount of air admitted isso regulated that the lowest temperature is at the top where the fuei isfed in, andY the temperature gradually and steadily increasing,beginning with the zone of nascent combustion corresponding to thetoplnost inlet and extending through a se# ries of zones of progressivecombustion, until the gas is discharged into the gas holder, this beinga part of my principle of gradual com-- bustion.

97 represents the distributing chamber which is simply a large chamberlocated in a convenient position to receive the gas after it has passedthrough the reducing zone 80, and to distribute it to the furnace, or tothe place or places where it is to be burned or utilized.

Figs. 1 and 2 ofthe drawings illustrateI the chamber and 112 is aremovable door througi.

distribution of the gas at several points of furnace suoli as isdescribed in my original application No. 294,594, iled January 4, 1906.In the examplel given in the illustration, the distributing chamber 97communicates, by means of horizontal passagesv 98 and 99, Fig'. 2, withthe gas fines 100 and 10i located immediately in the rear of theI seriesof combustion chambers on eitl'ier side of t e furnace. The distributingchamber and the passage leading therefrom to the furnace are provided atintervals with air inlet openin Im accordance with my principle' ofgradu... combustion, previously described. The gas dues 100 and lGl areclosed at the top, and communicate directly with a series of combustionchambers, l5 and 49, on either side of the furnace, through openings,such ldd.

30 and 81 represent air chimneys or as sages, Iwhich are connected tothe gas es 100 and 101 by passages 107 closed by valves 108.

Means are provided for cleaning the lov-rei." part of the producer anddistributing which the ashes may be raked out.

The air inlet openings 109 and 110 below the grate bars 93 and 94 areusually kept closed. and in this case the chamber 80 be# tween thesesets of grate bars acts as a reducing Zone, reducing, by the action ofthe incandescent coals'on said grate bars, any carbonio acid gas, (C02)`to carbon monoXid, (CO). lf it should happen that there is too large anaccumulation of coals on and underH neath the grate bars 94 the surpluscarbon may be easily and quickly burned by opening one or both of thetwo lowest air inlets, 109 and i l0.

ln the usual operation of the apparatus described, the air inletslocated below the grate 94 do not belong to the series of combustion airinlets previously described, and are not used. These air inlets areintended for use only for emergency purposes, as for example, 'when alarge mass of coals l'a"s through the lowest grate and it is necessary,for the proper working of the apparati; burn these coals.

in the form of producer above describal the fuel receptacle is anundivided chamber of single unit. The several Zones of the combustionseries described are not mechanicallj," separated from one another, butare defined, or designated, only by the correspoluling air inlets, andin o eration these zones merge one into the ot ier constituting a seriesof merging' Zones of progressive combustion as described.

Various forms of producers may be used for applying my method ol gradualprogress ive combustion according vto the luel util? 'ized or otherspecific conditions or reduire- 4- seance ducer in which the combustionzones are mechanically separated from one another by di visionalfloorsor grate bars of suitable material. The general construction of this isthe 5 same 4as already described, the parts 87, 88, 89, 90, 91, 93, 94,95, 109, 110,2nd 112 being er the construction already described. Inthis form of producer, however, the combustion chamber proper is dividedinto distinct zones by means of sets of grate bars 114, 115 and-117,'each of these zones being provided with an air inlet so that'thetemperature in such zone may be exactly regulated. In the drawings onlyfour combustion zones and but one air inlet for each Zone isshown, but

it is evident that any convenient number of combustion zones, and aplurality of such air inlets arranged at any convenient points aroundthe combustion chamber, might be in a cranked'portion 118 provided witha in 119 ada ted for o eration b an suita le l y ,IP y y means. he barso each grate are, of course,

I `connected together, so thatthey may be sivmultaneously operated.

Any convenient form of grate bars may be i' used, and any suitablemechanical device employed for o erating them. In the drawings dumpingars areshown, but shaking l grates or any other convenient form may beused. Whenplaced in position they should. e distance apart to permitthe' be set a suitab easy flow of gases between them. ln this .35vformof the producer, the fire is startedon the lower grate 93, and aftercombustion has sufficiently advanced the upper zones are filled orpartially filled with fuel and as required the fuel is dumped or shakenfrom 4D one Zone to the neXt succeeding in the line of advancingcombustion, always from a cooler; to a hotter zone. After each dischargea fresh shpply of fuel is charged into the top zone through-ho per 86and the o ieration repeated.y The fuel. is positively ivided intodifferent zones, in each of which the-tem erature may be accuratelyregu-- lated. he grates 98 and 94 are not dum'ping grates -but of theordinary construction,

`,50 as already described in connectionwith Figs. 1 and 2. 113represents the gas delivery pipe.

` Referring to Fig. 3, which illustrates the method of making,scrubbing, and storing producer gas, andgsupplying it to an, engine,

'1 re resents an explosive engine, of any desire pype, whichcommunicates by means of the pipe 2 with the gasometer 3, which is ofthe ,usual construction, havfing a bell 4 and "cuiiterebalancing weights5 connected vto 'said bell 4 by ropes passing over pulleys 6. 7represents a pipe connecting the fan Swith said gasometer, and 9represents "a pipe connecting said fan with the ripper part of 'thescrubber 10, which is filled with any desired used. The grates 114, 115, and 117 are dumping grates, each of the bars terminating purifyingmaterial, to the upper part 0f 65 which is sup lied a jet of waterthrough the pipe 11,v whic i is bent, as shown at 12, to pro. vide awater seal. 85 re resents the gas roduoer, and 113 the gas. elivery pipelea ing from the lower part of the producer into the lower part ofthescrubber.

lf desired, the air admitted through the air inlets 95 may be heated,but this is not usually necessary, 1

My method of producing gas is useful not only with the articular furnaceshown in Figs. 1 and 2 of) the drawings, but also with any kind of afurnace, and for heating, power, and illuminating purposes generallyafter being enriched, and may be used for producing gas from any kind offuel.

Having thus described my invention, what l claim as new and desire tosecure byLet.- ters Patent ofthe United States, is :f

.1. The process of producing gas'which 85 consists inburningfuelgradually and steadily in a series of progressive steps advancing fromincipient to complete oxidation, dividing the fuel body into a series ofZones correspending to the steps in the process of combustion andadmitting to each zone a measured volume of air proportional to thetemperature in such zone and just vsufficient to produce substantiallyequal increments of heat in each zone over the precedingzone,substantially as described.

2. The., process of producing gas, which consists in gasifying Yfuel'gradually and steadily ina series of rprogressive steps advancingfromthe incipient stage to complete y steadily in a series ofprogressivesteps advancing from incipient to completedecomposition,dividing the fuel into a series of zones corresponding to the steps inthe process of decomposition, admitting to. each zone a measuredquantity of air proportional to the capacity of the fuel at itsprevailing te'mperature in such Zone, to form anl intimatev chemicalunion with the air so admitted, the total quantity of air admitted beingsubstantially'just sufficient to produce complete 125 decomposition ofthe entire fuel mass, and in the progress of the process causing theproducts of decomposition to flow from each zone through and into thenext zone the series and always troni a cooler to a hotter zione,substantially es described.

4. The process of producing gas, which Vconsists in gasifying fuelgradually in a series oil Zones starting with incipient combustion in en-initial Zone and gradually growing hotter in euch succeeding zone untilcornplete gasification takes platee in the final zone, supplying 'fundercontrol measured quantities oi' air to such zones just sutcient to causesubstantially equal increments of heat in each zone over the precedingZone7 the quantity of air thus supplied to each zone being proportionalto the temperature ci? said Zone, and the capacity of the fuel therr'nto formen intimate cliernicalunion there with, the sum total ofthe airsupplied to all the zones being,l substantially just sufficient toproduce complete gasification, causing the Aluel and the products otconibustion to inove from one Zone to the next through the entire-seriesof zones, and always from a cooler to a hotter zone,` and finallycausing the incandescent i'uel and products of' combustion to nioveiri'to e reducing)r zone sealed against air, end causing the gssifiedproducts of combustion to pass through said reducing Zone and bedischarged therefrom at the hottest point of the operation, sulonstantinlly es described.

The process oi producing gas, which consists in dividing a column offuel into a series oi zones composed ofa plurality of combustion zonesandl one reducing zone at the end of the ser-ies, starting 'incipientcom hustion in the initial zone, and advancing the process oi"combustion regularly in each of the succeedin@ combustion zonessupplyingunder control to each combustion zone a measured quantity of airproportional to the quantity oi fuel in seid zone and to the capacity offuel in said Zone to form an intimate chemical unionl With the air thussupplied', sealing the'reducing zone of the series against the admissionof any extraneous air,

causing the fuel and the products of combust-ion in each zone to rnovein a continuous stream from one Zone to and through the next,startingwith the initial Zone and always moving to a hotter zone, andinally ,causin incandescent fuel to continuously move series into thereducin zone, and causing the gaseous products o ,"eornbustion to oW ina continuous stream into and through said ,reducing Zones and to bedischarged therefrom at the hottest point of the operation,substantially as described.

In testimonywhereof, ll aflix my signature in presence of two Witnesses.

WILLAM B. DENNIS.

Witnesses:

Guo. i?. Brenn, Mirncn G. CLEAR.

roin the last combustion Zone of the I

